VERY STRANGE PROBLEM with my 3D printer

[concetto.oku]

Hi everybody,
I built a few months ago my 3D printer like the RepRap but with the print area larger. I mounted a motherboard Minitronics v1.0 (whit Marlin_v1) and the rest of the components are RepRap. I use the softwere is Repetier-Host with Slic3r or Cura.
Everything works great, but takes out the unsolvable problem:
If I want to print something, the printer makes me the first 3-4 layers righteous, but then it goes crazy and begins to make a print path different from that of the g-code. For example, if I need to print a simple cylinder, it forms in the first 3 layers of perfect circles, but to the layer n. 4 extruder begins to break out of the circle and begins to make a linear path, after which resumed the circular path, but not on the layer n. 3, it print "in the air".
Please, if anyone has a solution, help me!

[Roxy]

It is possible you are trying to slice (and print) a flawed .STL file. I've seen that happen if the .STL file is not manifold. I suggest you take a known good design and try that. It is very possible the bad behavior stops. Try this cube and see if it prints ok:

[concetto.oku]

Thank you, I solved it!
The driver of the Y axis is overheated and gave me this problem